clocksource: Initialize cs->wd_list

commit 5b9e886a4af97574ca3ce1147f35545da0e7afc7 upstream.

A number of places relies on list_empty(&cs->wd_list), however the
list_head does not get initialized. Do so upon registration, such that
thereafter it is possible to rely on list_empty() correctly reflecting
the list membership status.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Diego Viola <diego.viola@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20180430100344.472662715@infradead.org
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 03918a19cf2da854bcefa9f8188daa53a7db82f4..3b71d859ee38eb0b6d1ccdd5a30b46a3b43c7bb6 100644 (file)
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -322,6 +322,8 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
        unsigned long flags;
 
+       INIT_LIST_HEAD(&cs->wd_list);
+
        spin_lock_irqsave(&watchdog_lock, flags);
        if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
                /* cs is a clocksource to be watched. */